(a) Technical Field
The inventive concept relates to a display device. More particularly, the inventive concept relates to a display device in which luminance of a light source is compensated according to lapse of time using the display device.
(b) Description of the Related Art
A computer monitor, a television, a mobile phone, and the like that are widely used need a display device. Examples of the display device are a cathode ray tube display device, a liquid crystal display, and a plasma display device.
The liquid crystal display (LCD) is one of the most widely used flat panel displays (FPD), and it is composed of two display panels on which field generating electrodes are formed, and a liquid crystal layer interposed between the two display panels. A voltage is applied to the field generating electrodes to generate an electric field on the liquid crystal layer, and the orientation of liquid crystal molecules of the liquid crystal layer is determined and the polarization of incident light is controlled through the generated electric field to display an image.
Since such a liquid crystal display is not self-emissive, a light source is required. In this case, the light source may be a separately provided artificial light source or a natural light source. The artificial light source used in the liquid crystal display includes a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), and an external electrode fluorescent lamp (EEFL).
Recently, a light emitting diode (LED) has been used as the light source of the liquid crystal display, however the light emitting diode (LED) has a drawback that the luminance is gradually decreased according to lapse of time using the display device. For example, the luminance is decreased to about 50% of initial luminance after one year of use according to a frequency used in a case of a general monitor.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art.